GPON is a point-to-multipoint optical access technology. The network architecture of GPON access is as shown in FIG. 1, in which, an Optical Line Terminal (OLT) is a central-office device of the GPON; an Optical Network Unit (ONU) is a user end device; the OLT is connected with the ONU through an Optical Distribution Network (ODN) formed by a passive optical splitter device; an ONU Management and Control Interface (OMCI) provides a management and control channel from the OLT to the ONU; in FIG. 1, a full line represents a service channel and a dash line represents an OMCI management channel.
Standard G.984 series of the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) is GPON technical standards, in which, G984.4 defines an OMCI standard. The G.984.4 specifically defines a general mechanism of the OMCI, related Management Entity (ME) and so on; the OLT configures the related ME through the OMCI, thereby implementing remote configuration and management of the ONU.
A GPON system mainly applies to application scenes such as Fibre To The X (FTTx), and supports the access of multiple services, including surfing the internet, Voice over Internet Protocol (VoIP), Internet Protocol TV (IPTV) and Circuit Emulation Service (CES). For a service born by an IP message, for example, VoIP, Pseudo-Wire Emulation Edge to Edge (PWE3) and so on, there is an instance of one or more IP host MEs on the ONU. Each IP host bearing a service must have a valid IP address; generally, the IP address of the IP host is statically configured (static) or automatically acquired through a Dynamic Host Configuration Protocol (DHCP), wherein the static configuration mode needs to occupy relatively more address resources and is complex to manage; and the DHCP mode has certain safety hazard.
A PPPoE is employed to establish a virtual connection between a user and a central-office authentication server, and the communication, negotiation and configuration of an IP address are performed on this connection. Since the PPPoE dial-up mode has higher security, stability and manageability and occupies relatively less resources, the PPPoE dial-up mode has been widely used.
At present, G.984.4 supports two modes, namely, static and DHCP, which are implemented by configuring an IP host config data ME, wherein the definition of the ME is as follows:                1. ME: IP host config data.        2. data relationship: association with an ONU ME, wherein Transmission Control Protocol (TCP)/User Datagram Protocol (UDP) ME created subsequently can direct to this ME.        3. ME attributes:        
3.1. ME id: this attribute uniquely identifies each instance of this managed entity. The ONT creates as many instances as there are independent IP stacks on the ONT; this attribute is read-only and mandatorily implemented, with a length of 2 bytes. The term “mandatorily implemented” refers that the requirement of an attribute field defined by an ME on a device is not optional but must be supported,                3.2. IP options: this attribute is a bit map table that enables or disables IP-related options, wherein value 1 indicates that the option is enabled and 0 indicates that the option is disabled;        0x1 Enable DHCP;        0x2 Respond to pings;        0x4 Respond to a traceroute messages;        0x8 . . . 0x80 Reserved;        this attribute is readable, writable and mandatorily implemented, with a length of 1 byte.        3.3. Media Access Control (MAC) address: this attribute indicates the MAC address used by the IP node, and is read-only and mandatorily implemented, with a length of 6 bytes.        3.4. ONU identifier: which is a unique character string of the ONU identifier; if the ONU identifier is set to be non-null, the character string is used instead of the MAC address when a DHCP parameter is acquired; if the character string is of less than 25 characters, the character string must be null terminated. The default value is 25 null characters. This attribute is readable, writeable and mandatorily implemented, with a length of 25 bytes.        3.5. IP address: which is an address used for IP host service, with a default value of 0 (not set); if this value is set, it would overwrite any value acquired through the DHCP. This attribute is readable, writeable and mandatorily implemented, with a length of 4 bytes.        3.6. Mask: which is a sub-net mask used for IP host service, with a default value of 0 (not set); if this value is set, it would overwrite any value acquired through the DHCP. This attribute is readable, writeable and mandatorily implemented, with a length of 4 bytes.        3.7. Gateway: which is a default gateway used for IP host service, with as default value of 0 (not set); if this value is set, it would overwrite any value acquired through the DHCP. This attribute is readable, writeable and mandatorily implemented, with a length of 4 bytes.        3.8 Primary Domain Name System (DNS): which represents the address of the primary DNS server, with a default value of 0 (not set); if this value is set, it would overwrite any value acquired through the DHCP. This attribute is readable, writeable and mandatorily implemented, with a length of 4 bytes.        3.9. Secondary DNS: which represents the address of the secondary DNS server, with a default value of 0 (not set); if this value is set, it would overwrite any value acquired through the DHCP. This attribute is readable, writeable and mandatorily implemented, with a length of 4 bytes.        3.10. Current address: which is the current address of the IP host service; an ONU updates this attribute after the DHCP assigns a new address. This attribute is read-only and optional, with a length of 4 bytes.        3.11. Current mask: which is the current subnet mask for the IP host service; the ONU updates this attribute if the DHCP assigns a new subnet mask. This attribute is read-only and optional, with it length of 4 bytes.        3.12. Current gateway: which is the current default gateway for the IP host service; the ONU updates this attribute if the DHCP assigns a new gateway. This attribute is read-only and optional, with a length of 4 bytes.        3.13. Current primary DNS: which represents the address of the current primary DNS server; the ONU updates this attribute if the DHCP assigns a new address. This attribute is read-only and optional, with a length of 4 bytes.        3.14. Current secondary DNS: which represents the address of the current secondary DNS server; the ONU updates this attribute if the DHCP assigns a new address. This attribute is read-only and optional, with a length of 4 bytes.        3.15. Domain name: this attribute indicates the domain name allocated by the DHCP; if no domain name is allocated, this attribute is set to be a null character string; if the character string is of less than 25 bytes, the character string must be null terminated. The default value is 25 null characters. This attribute is read-only and mandatorily implemented, with a length of 25 bytes.        3.16. Host name: this attribute indicates the host name allocated by the DHCP; if no host name is allocated, this attribute is set to be a null character string; if the character string is of less than 25 bytes, the character string must be null terminated. The default value is 25 null characters. This attribute is read-only and mandatorily implemented, with a length of 25 bytes.        
The inventor finds that the OLT configuring the IP host config data ME through the OMCI can adopt two modes, namely, static and DHCP, but cannot support accessing in a manner of PPPoE dial-up, because there is only one “Enable DHCP” option in the IP option field of 3.2; when this option is enabled, the configuration adopts the DHCP mode; when this option is disabled, the configuration adopts the static mode; and only one of the above two can be selected. Since the PPPoE dial-up cannot be configured through the OMCI and the accessing in a manner of PPPoE dial-up is not supported, the application of the GPON system is limited, which is not good for the development of GPON service.